Parshas Bo tells us of the end of the Jewish captivity in Egypt. As the last of the ten plagues is brought upon the Egyptians, the Jewish people gather in their homes to celebrate the first Passover and to eat of the Paschal offering.
The Torah describes the numerous requirements of this offering that continued to apply for future generations. Among other requirements, the offering had to be eaten roasted, no bones could be broken, and the meat could not be removed from the location of the meal. The classic 13th century work of mitzvos, Sefer HaChinuch, explains all of these requirements as serving to help us remember our miraculous exodus from Egypt.
The Sefer HaChinuch (Mitzva 16) then raises an important question. Why are all these details necessary? If the goal is simply to help us remember the past, then wouldn't a simple commemoration be sufficient? What is gained by all of these extra rituals and details?
The Sefer HaChinuch answers this question with a psychological principle which is one of the most basic concepts in the study and practice of mussar (character improvement). Stated simply, this principle is that our actions profoundly influence our character. As the Sefer HaChinuch puts it, "האדם נפעל כפי פעולותיו" - "Man is affected by his actions." Our hearts and minds are drawn after our physical actions, both for the good and for the bad. If we engage in good actions, even without the proper motives, the actions will gradually draw us towards becoming good people. And if, God forbid, we engage in bad actions, the actions will draw us towards becoming bad people.
For this reason, the Sefer HaChinuch continues, God gave the Jewish people numerous commandments, so that we would have numerous positive actions that make us into better people. It is therefore not surprising that God gave us numerous special commandments in connection to the Passover offering, as the exodus from Egypt is a "great pillar of our Torah" and needs to be firmly implanted in our hearts and minds.